Milton Friedman was bullshitting you: There is a lunch that's so low in opportunity cost that it's functionally free, and you will find it here on Monday, April 20, beginning at 11 am. Show up with the Leafly app on your intelligent telephone and the Hot Box BBQ cart will hook you up with a free sammy made of delicious smoked meats on brioche buns, plus chips and water. Bridge City Collective Southeast, 215 SE Grand Ave., bridgecitycollective.com. 11 am. Free.

4:20 at Mount Tabor

It's kind of an unofficial thing, but it's well-known enough that even The Oregonian has covered it, so stay off our collective ass about drawing attention to it. On 4/20, at 4:20 pm, a bunch of people from a variety of backgrounds who share one common interest tend to congregate on the grassy lawn atop Mount Tabor. And they tend to yell in unison. If you listen for a steady drumbeat, you will find this group, and if you stand near them, you will get a little smoky and may also be offered a drag. Southeast 60th Avenue and Salmon Street. 4:20 pm. Free.

Cannabis Corner Grand Opening Ceremony

The world's first city-owned weed shop holds a grand-opening party weekend. On Saturday April 18, growers and vendors set up tables to demonstrate their wares, and on Monday, April 20, the city of North Bonneville hosts an open-house celebration with the shop's staff, the Skamania County Chamber of Commerce, and people from the local cannabis community. The open house has free refreshments, raffles and a ribbon-cutting (giant scissors promised) from 5 to 7 pm. For more info, check facebook.com/nbpdacorner, @CannabisCorner1 on Twitter, and thecannabiscorner.org.

Ribbon-Cutting at High End Market Place

High End Market Place has been open for a few months now, but, uh, you know how it goes, right? By the time you get the sink to stop leaking and figure out the quirks in your POS system, there's a line out the door and you have more bills that need paying than ribbons that need cutting. Well, now this little shop in an old Vancouver Craftsman gets a proper christening with the chamber of commerce and Vancouver's square-jawed, TV-ready mayor, Tim Leavitt. The Voodoo Doughnuts truck is coming to pass out free doughnuts, there's live music on deck and special deals on Thai sticks, which should get you blazed enough to try breaking into the WSU-Vancouver ROTC to burn draft cards—or something. High End Market Place, 1906 Broadway St., Vancouver, Wash., 360-609-0364, highendmarketplace.com. Ribbon-cutting at noon, doughnuts 1-3 pm. Chronic grams for $4.20.

Don Carlos & Vieux Farka Touré with Manoj

They call this a "victory party on the road to cognitive liberty and the end of the drug war," and while we can't celebrate too hard with so many of our brothers and sisters still living under weed-free tyranny, this party has both legendary reggae singer Don Carlos, who is an original member of Black Uhru, and Malian guitar player Vieux Farka Touré. Wonder Ballroom, 128 NE Russell St. 9 pm. $22. 21+.

Mobb Deep

No weed-happy party rap here. For 20 years, Mobb Deep has kept it gritty and street with dark stories from its native Queensbridge. Its hardcore classic The Infamous, which turns 25 on April 25, thrives in the dark spots that Jay and the Wu crew only mention in passing—the sex is drunken and sloppy, the bail needs paid, friends are snitches, or friends are fucking wifeys, and they need to be shot. Mostly this happens on sparse, high-hat-heavy soundscapes. It's a grim but realistic world, and if you're not in the mood for positive vibes and scandalously dressed hunnies, this is your spot. Doug Fir Lounge, 830 E Burnside St., dougfirlounge.com. 9 pm. $20-$23.

Cannabis Cabaret

Live fire-dancing comes back to Dante's along with comedy, burlesque and aerial gymnastics at this annual celebration of weed culture. There are also gluten-free baked goods but they do not appear to be medicated, so think tinctures. Or just stand up close with an unlit jazz cigarette in your mouth and hope one of the dancers lights it. Dante's, 350 W Burnside St., danteslive.com. $12 in advance, $15 at the door. 21+.

Southeast Grind Birthday

Southeast Grind is a 24-hour coffee shop—yeah, totally different grinder here—that opened six years ago on April 20. To celebrate, they're offering $1 cups of chai and latte all day. If you want some caffeine to level out your buzz, this is an ideal place to get it. Southeast Grind, 1223 SE Powell Blvd., 473-8703, southeastgrind.com.

Party with food, drinks and music at the World Forestry Center. You don't need an OMMP card to attend, but you do need one to get into the tent where people are consuming the good stuff. Vendors will have flower, BHO and glassware, and a local lab will conduct a demonstration. The first 300 people who show up after RSVPing will get swag bags. World Forestry Center, 4033 SW Canyon Road, tinyurl.com/budtendersball. 7 pm-midnight. Reservations required; OMMP card required to enter smokers tent. 21+.